1. Field of the Invention
The present invention relates generally to a method for treating tobacco and to the tobacco produced by the method. In particular, the method is concerned with rapidly converting a cured tobacco into a tobacco having smoke, flavor and taste characteristics of a naturally-aged, cured tobacco.
2. Description of the Related Art
It is well known that freshly harvested tobacco generally requires several years of processing before is provides a pleasant smoke to a smoker. Typically, harvested tobacco is dried for several months in order to cure it. The cured tobacco undergoes several sweating or aging operations over a period of two to three years. During curing and aging, chemical changes in the tobacco increase the flavor and other desirable constituents and decrease harsh and less desirable constituents.
Conventional curing and aging has substantial economic drawbacks. First, the tobacco must be stored for a substantial period and cannot be processed into tobacco products until the curing and aging is complete. Second, storage and maintenance costs are substantial. Various equipment must be utilized to monitor and treat the stored tobacco. Voluminous warehouses are required to house the vast amounts of tobacco in storage.
Various attempts have been made to shorten the time necessary to convert freshly harvested tobacco into a smoking product which has desirable flavor and smoking qualities. For example, bacteria, enzymes, and other agents such as catalysts have been added to the tobacco in order to promote the chemical changes and accelerate the aging of the tobacco.
U.S. Pat. No. 3,256,888 discloses a process for treating tobacco. In the process, a proteolytic enzyme is added to a tobacco in an amount of 1.4 to about 2.8 grams of proteolytic enzyme per pound of tobacco.
Other processes have been developed for the flavor and aroma enhancement of tobacco and is smoke. Representative examples of such processes include the following U.S. Pat. Nos.: 187,924; 2,309,975; 3,256,889; 3,478015; 3,513,857; 3,920,026; 4,286,606; 4,306,577; and 4,537,204.
Consequently, a continuing need exists for improvements in methods for treating tobacco in respect of obtaining desirable end-use characteristics. In particular, a treating method which would reduce the time and treatment facilities otherwise required for the natural curing and aging process would be a significant advance in the art.
It is therefore an object of the present invention to provide an improved treatment which will accelerate the chemical processes which occur during conventional curing and aging, to produce a tobacco with high quality taste and flavor and reduced harshness.